Gastester is a digital exhaust Carbon Monoxide (CO) analyser with pulse pump that accurately measures CO levels for testing and setting carburettors (leaded or unleaded petrol) and petrol injection systems on any vehicle. The digital display clearly indicates the volume percent of carbon monoxide so the engine can be tuned for optimal performance to run cleaner and more efficiently. Ideal for checking CO after carburettor, ignition and air filter maintenance as well as tuning pre-cat classic cars, motorbikes and single cylinder engines. The system is easy to use, a metal exhaust probe is held in place with a pair of retaining springs and a length of flexible pipe attaches the probe to the Gastester. The kit includes everything needed for accurate CO testing and is supplied with full instructions.